Acoustic Rashba-Edelstein effect

TL;DR

This paper theoretically investigates how lattice dynamics induce spin density in Rashba systems through two mechanisms, revealing a highly efficient spin generation process that surpasses conventional methods.

Contribution

It introduces and analyzes two mechanisms of spin induction via lattice dynamics in Rashba systems, highlighting the efficiency of the acoustic Edelstein effect.

Findings

The acoustic Edelstein effect (AEE) is more efficient for spin-to-charge conversion than the electric Edelstein effect.

Spin density induced by Rashba spin-vorticity coupling can be described as a Berry curvature-like quantity.

High-efficiency spin generation is demonstrated in Rashba systems.

Abstract

We theoretically study the mechanical induction of the spin density via the Rashba spin--orbit interaction (SOI). The spin density in the linear response to lattice distortion dynamics is calculated based on the microscopic theory. We reveal that there are two mechanisms of spin induction: one is the acoustic Edelstein effect (AEE) from the acceleration of the lattice dynamics and the other is caused by the Rashba spin--vorticity coupling (RSVC). We find that the AEE induces a more efficient spin-to-charge conversion in comparison with the conventional electric Edelstein effect. The induced spin density due to the RSVC is expressed as a Berry curvature-like quantity; therefore, it can be attributed to the spatial symmetry breaking due to the Rashba SOI. Our work demonstrates high-efficiency spin generation in Rashba systems.